Compatibility
Most tray-loading CD devices have 2 'wells'; one sized for a normal CD, and a smaller, deeper well for MiniCDs to fit into.
Devices that feature an opening lid have no problem with MiniCDs, as the disc can simply be placed onto the spindle as with a normal CD.
Some vertically aligned tray-loading devices, such as the
PlayStation 2 when placed vertically, require an adaptor for use with 80 mm CDs.
Slot-loading CD drives are generally incompatible, (the iMac of 1999 is an exception), but adapters are available that one can snap an 80 mm round miniCD into to extend the width to match that of a 120 mm CD, and thus work in many slot-loading devices. There are no adapters for business-card sized CDs.
The
Nintendo Gamecube uses 80mm discs for all software.